A 14-year-old boy sustains a fracture of the lateral condyle of the humerus. If this fracture is not recognised and treated, the most feared late complication is:

• A Medial epicondyle avulsion with ulnar nerve palsy
• B Cubitus valgus deformity with delayed tardy ulnar nerve palsy ✓
• C Cubitus varus deformity causing cosmetic deformity only
• D Avascular necrosis of the lateral condyle

Explanation

Malunion of a lateral condyle fracture results in progressive cubitus valgus as growth continues, because the lateral physis is damaged. The valgus deformity stretches the ulnar nerve in the cubital tunnel over years, causing tardy (delayed) ulnar nerve palsy — weakness of intrinsic hand muscles and clawing of the ring and little fingers. This is a classic late complication seen many years after the original injury.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.